Exchange time/date tags

[jcharmon]

I have a collection of about 280 images I created by shooting 6x6 cm negatives with my Nikon as RAW images and then developing with DxO (i.e, ~140 images in each category). Because they were old negatives, I needed to assign the dates the original photos were taken. (As I now know, the whole subject of EXIF/XMP dates is rather complicated, as discussed in the Metadata Working Group Guidelines.)

Unfortunately, I managed to assign the desired (old) date to 'XMP xmp\Created Date' (which should be the date/time the image was created by the camera) instead of to 'XMP Photoshop\Date Subject Created'.

What would be the best way to swap the contents of these two metadata fields?

[Phil Harvey]

You can do it like this:

exiftool "-xmp:datecreated<xmp:createdate" "-xmp:createdate<xmp:datecreated" FILE

- Phil

[jcharmon]

Thanks; however, that didn't seem to work. The original metadata field values are unchanged, not swapped, in my test file.

I tried to upload the NEF (9052 KB) but the upload failed....

[jcharmon]

If the test file would be helpful, how can I send you a download link?

[Phil Harvey]

What do you mean by "didn't seem to work"?  How did you look at the metadata afterwards? Did ExifTool say the file was changed?  If so, what was changed?  Try adding the -v3 option when writing to get details about what ExifTool is doing.

Also, what is the output of this command on the original file?:

exiftool -xmp:datecreated -xmp:createdate FILE

(ie. does it contain the information we are trying to swap?)

- Phil

[jcharmon]

The problem seems to the fields selected:

Code Select Expand

exiftool -xmp:datecreated -xmp:createdate test_.nef
Date Created                    : 1953:11:01 12:00:00Z
Create Date                     : 1953:11:01 12:00:00Z

No wonder the data in the file didn't change! (Which is what I meant by 'ExifTool didn't seem to work'.)

Code Select Expand

exiftool -v3 "-xmp:datecreated<xmp:createdate" "-xmp:createdate<xmp:datecreated" test_.nef
======== test_.nef
Setting new values from test_.nef
Writing XMP-photoshop:DateCreated
Writing XMP-xmp:CreateDate
Rewriting test_.nef...
  Editing tags in: IFD0 TIFF XMP
  Creating tags in: IFD0 TIFF XMP
  FileType = NEF
  MIMEType = image/x-nikon-nef
  ExifByteOrder = MM
  Rewriting IFD0
  Rewriting SubIFD
  Rewriting SubIFD1
  Rewriting XMP
    - XMP-xmp:CreateDate = '1953-11-01T12:00:00Z'
    + XMP-xmp:CreateDate = '1953-11-01T12:00:00Z'
    - XMP-photoshop:DateCreated = '1953-11-01T12:00:00Z'
    + XMP-photoshop:DateCreated = '1953-11-01T12:00:00Z'
  Rewriting IPTC
    [nothing changed]
  Rewriting Photoshop
  Rewriting ExifIFD
  Rewriting MakerNoteNikon
  Rewriting PreviewIFD
  Rewriting VRInfo
  Rewriting PictureControlData
  Rewriting WorldTime
  Rewriting ISOInfo
  Rewriting UnknownInfo
  Rewriting ShotInfoD90
  Rewriting ColorBalance0211
  Rewriting LensData0204
  Rewriting FlashInfo0103
  Rewriting MultiExposure
  Rewriting AFInfo2
  Rewriting FileInfo
  Rewriting GPS
  Copying 2 image data blocks
    1 image files updated


I've attached an ExifTool dump of the file metadata. The specific fields from the dump I need to swap (I think) are:
[Composite]     Create Date                     : 1953:11:01 12:00:00.00
[Composite]     Date/Time Original              : 2011:10:15 13:12:46.00
[Composite]     Modify Date                     : 2013:03:22 16:15:28.00

That is, the
[Composite] Date/Time Original should be 1953:11:01 12:00:00.00 (the date/time the original photo was taken)
and the
[Composite] Create Date should be 2011:10:15 13:12:46.00 (the date/time I photographed the original photo with my digital camera).

Of course there are several metadata fields with these date/times in the field; my problem seems to be choosing the right ones, and using the right syntax for them in an ExifTool command.

[Phil Harvey]

OK.  I think that reading FAQ number 3 should answer your questions.

- Phil